So we have put together as crash course in etiquette for dummies - sorry, footballers - to help Wayne Rooney and co. stay in Van Gaal's good books.

1) Try not to dribble in public

There was a time when the sight of Welsh wizard Ryan Giggs flying up the wing was enough to have the Old Trafford faithful drooling over their prawn sandwiches.

However, times have changed and the fact that Giggs and Cristiano Ronaldo have made way for Michael Carrick and Maroune Fellaini just goes to show that dirty habit of dribbling is no longer tolerated in the red half of Manchester.

2) Don't talk back to the boss

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Of course the Manchester United players should already be familiar with this particular rule after years of tyranny under Sir Alex Ferguson.

Those who dared to speak out in the dressing room could expect to be booted back into line - literally. Who could forget the time David Beckham incurred Fergie's fury and took some flying footwear to the face? Except perhaps Becks himself, after all that boot hit him pretty hard!

3) A gentleman should never kiss and tell

And in the case of Ryan Giggs, no-one else should speak about it either. The new United assistant manager was once considered the perfect example of a clean cut pro until rumours about his love life began to circulate.

Ever the chivalrous chap, Giggs sought to defend the honour of the damsels he had bedded (including his own sister-in-law) by seeking a super injunction to stop the media reporting his lurid love life.

4) Learn to share

(Image: John Peters)

A lesson Sir Alex Ferguson never learned as the Scot notched up 13 Premier League titles, five FA Cups and two Champions League crowns during his time at Old Trafford.

However, his successor David Moyes was more magnanimous and immediately set about allowing some of the smaller boys to enjoy a taste of success, even letting Swansea win at Old Trafford for the first time.

Moyes' early exit suggests not everyone around Manchester United has mastered the art of sharing yet, especially not with their Manchester neighbours City. But unless Van Gaal is given significant funds to overhaul his struggling squad it is a lesson the fans may have to learn sooner rather than later.

5) Don't play with your food

Another rule that Sir Alex would no doubt welcome after he was caught in the crossfire in the infamous Battle of the Buffet that kicked off in the tunnel after an ill tempered match between United and old rivals Arsenal at Old Trafford in 2004.

Teenage prodigy Cesc Fabregas has since been named as the man who threw a pizza at Fergie, forcing him to change his suit before his post match interview but we can imagine there were a few other Gunners stars who wanted a slice of the action.

6) Love your elders (no Wayne, not like that!)

England striker Wayne Rooney was only 16 when he scored with sex worker Patricia Tiernan, 54, but it turned out to be an own goal when news about his romp with the “Auld Slapper” was leaked.

That aside a healthy respect for your elders is an absolute must at Old Trafford with Van Gaal already aged 62, while club directors Fergie and Sir Bobby Charlton are 72 and 76 respectively.

7) It's rude to discuss money in public

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Especially when you are paid obscene amounts of money for kicking an artificial pig's bladder around a field. Rooney's current contract is reportedly worth £300,000 a week – enough to pay for 520 hospital nurses – and that's before all his advertising earnings are taken into account.

Mind you, we'd still prefer to talk wages with Wayne than speak about sexism or women's rights with Andy Gray, Richard Keys or Premier League chief executive Richard Scudamore.

8) Always remember (and celebrate) friends' and family's birthdays

Okay, so this lesson is probably more appropriate for the blue half of Manchester but it never hurts to learn from someone else's mistakes.

In this crazy modern world it's easy to feel neglected when you see your pal being given a flash Bugatti supercar for their birthday while you have to settle for a cake and a paltry £300,000 per week. So if someone you know is celebrating a birthday try to make time to shake their hand and wish them well.